The proposed research will investigate the role of cognitive/social processing in maternal distress associated with pediatric bone marrow transplantation (BMT) in the treatment of pediatric cancer. Although heightened levels of distress among these mothers has been documented in clinical studies, little is known about the course of such distress during and after BMT or factors that place mothers at increased risk for adjustment problems. The research is guided by the integration of current models of cognitive/social processing. According to these models, the psychosocial impact of severe negative life events is related to how well the individual is able to integrate the event into his/her beliefs. This recovery process can be stifled when social constraints on talking about the event exist. In the proposed longitudinal analysis 509 mothers will be recruited to participate in a series of five structured interviews during the course of their child's BMT. Assessments of psychosocial and background factors will be conducted two weeks before BMT hospitalization, during the acute BMT hospitalization, and at 6, 12, and 18 months post-BMT. Specific aims are to: 1) examine the course of psychological distress among mothers of children undergoing BMT; 2) determine the role of cognitive and social processing in the development and maintenance of mothers' psychological distress during and after their children's BMT; and 3) assess how dispositional optimism, monitoring coping style, and prior negative life events influence mothers' cognitive processing and development/maintenance of psychological distress. A combination of latent growth curve and structural equation modeling will be used in the data analysis.